Saline lakes watershed extents update

Objective

The objective of this report is to update and display the latest version of our spatial data from which we are collecting water quality and availability data across the relevant watersheds of our selected saline lakes in the Great Basin Desert.

Defining our geospatial features

• Water body and watershed extent definitions:

  • Saline Lakes: The saline lake waterbody spatial geometry. Spatial polygons stem from the National Hydrography Dataset Plus high resolution (NHD) database, USGS’s primary database for US-wide hydrological network. The boundary of the layer is the border of the water body feature, and excludes wetland areas that are found beyond the waterbody boundary.

  • Watershed Extents: Aggregation of hydrologic unit (HUC) boundaries obtained from the National Hydrography Dataset (NHD) Plus High Resolution (NHDhr). These watershed polygons of each lake include the lake waterbody and the surface hydrologic features that flow to the lake. The creation of this geospatial dataset draws upon the defined hydrologic unit (HUC) boundaries from NHDhr (HUC6, HUC8, and HUC10) as well as SME feedback provided by members of the project team.Note: 6-digit HUCs (HUC6) are basins, 8-digit HUCs (HUC8) are subbasins and 10-digit HUCS (HUC10) are watersheds.

  • USGS NWIS gage sites: Point locations where water measurements have been collected, whether at regular intervals (continuous (15 min), or daily) by permanent USGS gages or field measurements by a USGS staff.

  • Lake boundary including wetlands: TBD

Data source table

Feature	Source/Database	Notes
Water bodies	National Hydrological Dataset - high res - water body attributes	The nhdplusTools R package was used to collect this data. Carson sink was manually drawn and appended to the lakes geospatial file
HUC boundaries	National Hydrological Dataset - high res - HUC6,8,10,12	The nhdplusTools R package was used to collect this data
Flowlines	National Hydrological Dataset - medium res - NHDFLowlines	The nhdplusTools R package was used to collect this data
Gage sites	NWIS	The NWIS dataRetrieval R package was used to collect these site
water measurements	NWIS	The NWIS dataRetrieval R package was used to collect these data metrics